Nucleof446 UART

harry123 · ‎2024-09-25

Hi

I am trying to communicate between arm processor and nucleo board through uart
The processor has a type b usb , to interface with computer.
For the same usb I am connecting my Nucelo board through usb type B mini and sending the data through it
When i connect the device to laptop/computer the communication happens, and when i connect nucleo the communication does not happen.
Im giving both power supply and uart communication from usb cable.

Andrew Neil · ‎2024-09-26

@harry123 wrote:
Will the same STM UART transmit receive code that is used for VCP i.e teraterm/putty works for AT91SAM

The whole point of the standard USB device profiles is that the device is completely oblivious to the nature of the host - it neither knows nor cares whether the host is a PC or a Mac or some sort of Linux or whatever.

Similarly the Host is completely oblivious to the nature of the device - it just sees a standard Virtual Serial Port.

So the question is: does your SAM board support a VCP?

You can easily find out by just plugging it in - does a VCP device appear?)

It will probably appear as a /dev/ttyACMx (maybe a /dev/ttyUSBx) ::(:(:(

https://community.st.com/t5/stm32-mcus-products/communication-between-nucleo-f411re-and-raspberry-pi-using-st/m-p/721528/highlight/true#M261168

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

View solution in original post

Andrew Neil · ‎2024-09-25

@harry123 wrote:
I am trying to communicate between arm processor and nucleo board through uart
The processor has a type b usb , to interface with computer.

So this "ARM processor" has a USB Device connection.

The CN1 USB connector on your Nucleo board is also a USB Device connection:

You cannot connect two USB Devices together - a Device can only connect to a Host.

@harry123 wrote:
When i connect the device to laptop/computer the communication happens

That's because the computer is a Host.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Andrew Neil · ‎2024-09-25

What is CN2?

Is that a USB Host port?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

harry123 · ‎2024-09-25

YES That USB type A port is used to interface a printer
and another port USB type is is used to interface with a computer.
And I want to have communication between Nucleo and Processor ( I have attached pdf of processor) .

Andrew Neil · ‎2024-09-25

@harry123 wrote:
I want to have communication between Nucleo and Processor

The CN1 USB connector on your Nucleo board is a USB Device connection for the Virtual COM Port (VCP) in the ST-Link:

https://community.st.com/t5/stm32-mcus-products/communication-between-nucleo-f411re-and-raspberry-pi-using-st/m-p/721571

To use that, you must connect it to a USB Host port. That's the way it works.

Instead of using this USB connection, could you use a direct logic-level connection to one of the UARTs on your ARM9 board?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Andrew Neil · ‎2024-09-25

@harry123 wrote:
YES That USB type A port is used to interface a printer

Does it support a Hub - then you could use it for both the printer and the ST-Link VCP ... ?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

harry123 · ‎2024-09-25

It is the pin PB4 and PB5 of arm processor which is connected to USB device and Interface is happening through PC/laptop. Like sending the data and receving the data.
Can I try connecting PB4 and PB5 and GND of arm processor directly to the USART1 pin PA9 and PA10 and GND of my nucleo board through J25(in image)
Will the logic level be same between both the boards.
Thank you

Andrew Neil · ‎2024-09-25

@harry123 wrote:
Can I try connecting PB4 and PB5 and GND of arm processor directly to the USART1 pin PA9 and PA10 and GND of my nucleo board through J25(in image)

Which "ARM processor" are you talking about? Both the STM32 and the AT91SAM9G45 are ARM processors!

@harry123 wrote:
Will the logic level be same between both the boards.

You need to study the board documentation for that.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

harry123 · ‎2024-09-25

AT91SAM9G45 processor.

Andrew Neil · ‎2024-09-25

There's not enough information in that brief document - you need a more detailed technical manual.

But this Mini6045 board seems to be obsolete and no longer supported - so no idea where you'll find that.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.